World of Sudoku

Well, I think recently I am obsessed with sudoku the number puzzle game which has taken the world by storm. Ha, I strongly urged people to visit the website websudoku.com .There are billions of puzzles and the great thing about this is you can keep doing and doing.

I have yet to try hard or evil but am now trying to solve the easy puzzle within 6min average.(My record so far: 5min 14sec.) Well, it gets fun when you know that you can solve a puzzle in a certain timeframe and the website also tells you your ranking among the people who have solved the sudoku without any mistakes. Sudoku only has one solution which makes it appealing to me since I do not have to think about too many things but amazingly it gets harder as there are more possibilities if you proceed to medium hard and evil since they only provide few numbers. The idea of the game is simple: every row and column must not have the same number and you can only input numbers from 1 to 9. Simple yet can be challenging when you try to solve it as fast as you can.

Well, that's just something abt Sudoku to share with people who likes to solve this kind of puzzle or are interested to do so... :)

OOPS

1 month since I last wrote the last blog that is really bad... Anyway, here I am back again. Well, after the trauma of failing first driving test and how things could've been so different from the warm up I guess life still has to go on....
Well, I don't like to cry over spoilt milk. Here's sth for everyone who has been using soap... The article is about 'antibacterial' soap and 75% of liquid soap in American shelves display that on their labels. However, that doesn't mean we are actually cleaner than ever! Soap is made by combining an acid and a base. The acid is fat ( fatty acids and triglycerides) and base is soldium hydrochloridethe mixture causes the fatty acids to separate from the triglycerides and fuse with hydroxide ions. Soap's function is to decrease water's surface tension and to bind to dirt, oil and bacteria. This could be done because one part of soap molecule is water-binding and the other is water repellent.
" The hydrophilic part allows the hydrophobic fatty acids to come into contact with other hydrophobic substances, such as the dirt on the surface that is being cleaned. When the grime adheres to the soap's fatty acids, it becomes encapsulated in droplets of water."
So how does antibacterial soap get rid of more? Well, th pts to consider are: antibacterial componenets of soap need to be left on the surface for 2 minutes or more in order to work.Bacteria may develop a resistance to bactericidal agents over time. Some bacteria are actually beneficial. Normal bacteria eat our sweat and may help us defend against truly harmful bacteria. Some diseases are viral and so antibacterial soap also not effect..
Hey, the best way is just to use ordinary soap and wash hand thoroughly with warm water

Barcelona vs Chelsea at Nou camp

Hey this gotta be a disappointing match to watch as Chelsea was leading 0-1 by halftime through a Belleti own goal in the 33 min. I managed to wake up in time for this match unlike the day b4 for the match b/n Rela vs Juve.

Chelsea was basically desperately defending for first 30 min. And suddenly a pass to Duff from Frank Lampard, then it looked like a deflection from the barca keeper and Belleti turned into his own net while trying to clear the ball. And 2 minutes later a missed chance for Drogba for a one-on-one with the keeper. Suddenly, the tables looked to be turned against Barca. Eto'o and Ronaldinho couldn't hit any decent shots into the direction of Petr Cech.

The game erupted into controversy in the 55th minute when Anders Frisk red-carded Didier Drogba for what appeared to be nothing more than a 50-50 challenge for the ball with goalkeeper Victor Valdes.And on seeing the red, I was really angry with the decision of the referee. Yes, Drogba was a bit physical in the first half having conceded a yellow card but i think the knock against the Barca keeper Valdes was just unavoidable and he did not have the intention of bringing the keeper down instead it was a 50-50 situation. Drogba trying to kick the ball while the keeper rushing to get the ball.

Then the substiture Maxi from the Nou camp scored a goal in the 67 min within minutes of coming into the game and then Barcelona keep attacking from all flanks since they have the numerical advantage upon the dismissal of Didier Drogba. All hats to Petr Cech who had to endure enless shots at the goal. If not for him Chelsea could have been downed by more than 2 goals. And the 2nd goal from Samuel Eto'o was astounding to watch as he sneaked in b/n 2 defenders to connect with Maxi's pass into the penalty area and the ball was too fast for Cech to do anything about it. That was the 73rd min. And Barcelona keep on attacking while Chelsea were doing all they can to stop the attack.

This match would have been nice to watch if Chelsea were to have 11 men against 11 men. However, it was really disappointing to watch a one-sided game when Chelsea were reduced to 10 men. Well, I think in the previous game Mourinho made the mistake of substituting 3 players namely gallas, duff and bridge to turn the tides when Chelsea were down 1-0 to newcastle. All 3 were injured and bridge being the most serious possibly rest of the season sidelined. Hmm, well if Mourinho were not so ambitious to aim for a quadruple maybe Chelsea would have a better preparation for this match against Barca. But then again, I think Chelsea really need to purchase more attackers to really challenge for a quadruple. Their defence is good enough. Quality replacements for Arjen Robben and Duff should be in place in case the 2 are injured. And definitely better strikers are needed as Kezman is a total flop. I would think faster strikers would be an adv. Hopefully Tevez is coming to Chelsea soon. Maybe Owen could be a good choice also. Well, I do not have much hope for Chelsea to do well in the next leg against Barca since we still lack the attacking abilities of Robben and Drogba...

Chelsea FC

I've always like chelsea since the days of Zola and Flo (dwarf and giant). Although at that time, there were a lot of foreign talents and not really much of local english talents I like the interesting characters such as the 2 mentioned soccer players.
Gianfranco Zola who is like less than 1.6m, really makes his presence felt.In early 2003, Gianfranco Zola was voted as the best ever player of the team by the Chelsea fans. Whenever I see zola and flo play in the match i would be thinking abt the dwarf and the giant in the same team and playing together so well ha. There were also players like Di matteo, Dutch goalkeeper Ed de Goey, Nigerian defender Celestine Babayaro, dennis wise and defender graeume le saux. I remember the time when Ruud Gullit who was then a Dutch midfielder from Sampdoria who joined chelsea in 1995... and a year later became the Chelsea manager. Well, at least he made history by being the first foreign manager to win the FA cup in the 96-97 season when Chelsea beat boro 2-0. However, there was a dispute b/n the board of directors over transfer funds and thus he was sacked.
Italian striker Gianluca Vialli took over as player-manager and quickly established himself by winning two major competitions - the League Cup and the Cup Winners Cup. Well, as a Chelsea fan i really think there is an interesting history going on. 2 player managers taking over the club in a row and yet they did well in the league so far. However, vialli was sacked in 2000 when he guided chelsea to a FA cup win. And in came Claudio Ranieri the tinkerman....
Ranieri 's biggest achievement was to guide chelsea to the runners-up pos after Arsenal in the league. Despite this, Ranieri was sacked by the club's new owner Roman Abramovich - who had already ploughed almost £300million into the club. His successor was Jose Mourinho, who had just quit as coach of Portugese champions FC Porto despite winning the European Cup.
Well, the champions league first leg of the last 16 is coming soon and I really hope chelsea to at least snatch a draw from this difficult against barcelona. Mourinho has lost key players like wayne bridge and Robben through injuries and has to make do with some key players still having injuries like duff and Gallas who are doubtful to start and should be on the bench. This match would be a victory for Chelsea if they were to overcome the attacking prowess of Samuel Eto'o, Deco and Ronaldinho by snatching a draw in my opinion due to the current injury crisis in the squad... Well for Chelsea fans let's cheer them on!
And one thing which i think Chelsea lacks is world star players like Ronaldinho or Shevchenko who i think could strengthen the attacking power. Well, at least I am impress with the fact that we do not have any best players in Europe in the team but yet doing so well in the league.

Firewall

Oops, it has been quite a while since i last wrote... now writing again. Well, today's topic is firewall which is really sth very impt to protect information on the computers. Basically, a firewall is a barrier to keep destructive forces away from your property.

Firewalls use one or more of the methods below to ctrl traffic in and out of the network:

• Packet filtering - Packets(small chunks of data) are analysed against a set of filters. Packets that made it through the filters are sent to the requesting sysytem and the others are discarded.
• Proxy service - Info from the internet is retrieved by the firewall and then sent to the requesting system and vice versa.
• Stateful inspection - Basically examine contents of each packet and then compare the key parts of packet to a database of trusted info.If the comparison yields a reasonable match, the information is allowed through. Otherwise it is discarded.

Making the Firewall Fit

• Ip addresses - Each machine is assigned an unique address known as ip add which are 32 bits numbers(eg: 216.27.61.137). If certain IP add is reading too many files from the server, the firewall can block traffic to and from the IP address.
• Domain names - basically string of characters which seem to be easier to read than IP address. Can be blocked also.
• Protocols - pre-defined way that 'someone or sth' who/which wants to use a service talks with that service. Some common protocols that you can set firewall filters for include:

1. IP(internet protocol) - the main delivery system for info over the internet.
2. HTTP(hyper text transfer protocol) - used for webpage.
3. FTP(file transfer protocol) - used to download and upload of files.
4. telnet - used to perform commands on a remote comp.
5. TCP (Transmission Control Protocol) - used to break apart and rebuild information that travels over the Internet

A company might set up only one or two machines to handle a specific protocol and ban that protocol on all other machines.

• Ports - Any server machine makes its services available to the Internet using numbered ports, one for each service that is available on the server
• Specific words and phrases - This can be anything. The firewall will sniff (search through) each packet of information for an exact match of the text listed in the filter. for instance, you could ask the firewall to block any packet that contains the word "tele" in it.

A software firewall can be installed on the computer in your home that has an Internet connection. This computer is considered a gateway because it provides the only point of access between your home network and the Internet.

There is also the hardware version of firewall.In this case, the firewall itself is the gateway. "A good example is the Linksys Cable/DSL router. It has a built-in ethernet card and hub. Computers in your home network connect to the router, which in turn is connected to either a cable or dsl modem. "

What it protects you from

Remote login - This is when someone is able to connect to ur comp and ctrl it in some ways(viewing files or copying files).

Application backdoor - backdoor is the hidden access that provides some level of ctrl of the prog.

SMTP (Simple Mail Transport Protocol) session hijacking - It is the most common method of sending email over the internet and by gaining acess to a list of email addresses, someone can send unsolicited junk emails to lots of users. This is done quite often by redirecting the e-mail through the SMTP server of an unsuspecting host, making the actual sender of the spam difficult to trace.

operating system bugs - some OS have backdoors while others provide remote access with insufficient security controls or have bugs that an experienced hacker can easily take adv.

denial of service - This type of attack is nearly impossible to counter. The hacker sends a request to the server to connect to it. When the server responds with an acknowledgement and tries to establish a session, it cannot find the system that made the request. Byflooding a server with these unanswerable session requests, a hacker causes the server to slow to a crawl or eventually crash.

email bombs - someone would send u the same email message a thousand times or so to make ur email system crash

macros(script of comms the apllication can run on) - Hackers take adv by creating macros that may destroy data or crash the comp.

viruses- basically a small program that can copy itself to other computers.

spam - normally harmless but irritating to the core. Be careful of clicking on the junk emails because you may accidentally accept a cookie that provides a backdoor to your computer!

Redirect bombs - hackers can use ICMP(Internet Control Message Protocol) which is used to change the path info by sending it to other routers. This is one way in which denial or serv works.

Source routing -" In most cases, the path a packet travels over the Internet (or any other network) is determined by the routers along that path. But the source providing the packet can arbitrarily specify the route that the packet should travel. Hackers sometimes take advantage of this to make information appear to come from a trusted source or even from inside the network! Most firewall products disable source routing by default. "

Proxy Servers and DMZ

A function which is often combined with the firewall is a proxy server. Proxy server is used to access webpages by other comp. When another comp makes a request of a webpage, it is retrieved by the proxy server and the info would be sent to the requesting comp therefore there is no direct contact with anything on the home network.

Proxy server can make internet access more efficient. This is so as the webpage is cached(stored) on the proxy server when u access it so that the next time u access it it will load faster ...Sometimes, you would want remote users to access ur network such as website, online business and FTP download and upload. Thus, you would want to create DMZ(demilitarized zone)Think of DMZ as a front yard where u can put ur things outside the firewall and the more valuable thing swould be properly secured in ur house. "Setting up a DMZ is very easy. If you have multiple computers, you can choose to simply place one of the computers between the Internet connection and the firewall. Most of the software firewalls available will allow you to designate a directory on the gateway computer as a DMZ. "

This is abt it. Anyway, I would strongly recommend ppl to use firewall like Zonealarm(free) , or if u have any firewall software be sure to test it at www.grc.com.

Digital camera - part 3

Lens and Focal length

Most important diff b/n digicam and a 35mm camera is the focal length which is the distance b/n the lens and the surface of the sensor.The surface of a film sensor is larger than a CCD sensor. These are the four different types of lenses on the digicam:

• fixed-focus, fixed-zoom lenses: found on disposable and inexpensive film camera
• optical zoom lenses with autofocus: you'll have 'wide', 'telephoto' options and automatic focus (similar to lens on video camcorder).
• Digital-zoom lenses: camera takes pixels from center of image and "interpolates" them to make a full-size image.May produce grainy pictures- same effect if u use software to edit
• Replaceable lens system: High-end digicam can use this system and can even use lenses from 35mm cameras in some cases.

Some important information here:

Focal length 35mm film cam equivalent view typical uses
5.4mm 35mm Things look smaller wide-angle shots, lands
farther away apes, large buildings
grps of ppl
7.7mm 50mm abt same as wat eye "normal" shots of ppl
sees and objects
16.2mm 105mm things are magnified Telephoto shots, close
and appear closer ups
i try editing table but looks like the whole table shifts down a lot sorry for the inconvenience caused just read chronologically... should be able to get it.

Optical zoom vs Digital zoom

An optical zoom actually changes the focal length of the lensand thus image is magnified by the lens sometimes called optics, hence the name optical zoom.Light is spread across the entire CCD sensorand all pixels can be used.

Digital zoom magnifies a portion of image that hits sensor. If ur shooting image with 2x digital zoom, camera will use half of the pixels at the center of CCD, ignore other pixels and use interpolation techniques to add detail to photo.Basically same as magnifying on computer software...

Summary

You aim at subject with camera and adjust optical zoom to get closer of further away. You press the shutter release lightly. The camera automatically focuses on subject and take a reading of the avail light. It sets the aperture and shutter speed for optimal exposure. You press the shutter release all the way and CCD is reset and then exposed to light building up electrical charge until shutter closes. The ADC measures the charge and creates digital signal that represent the calues of the charges at each pixel. A processor interpolates the data from diff pixels to create natural colour. The processor may perform a preset lvl of compression on the data. The info is then stored in some memory device like flashcard.

What i Think
If ur looking for quality then look out for optical zoom and digicam with CCD sensor. Digital zoom is not that important if ur looking at magnifying images, this can easily be done with computer software. Of course, if ur looking at cheap cameras and just want to have fun with photos but don't really matter abt quality go for cameras with CMOS... If u only want images to post on website or email to frens 640x 480 resolution is enough (307200 pixels)To enlarge photo prints 2 or 3 megapixels but i guess most cameras are ard there...

Digital camera - part 2

Digitizing information
Light is converted to electrical charge. However, electrical charges are not in digital signal. Thus, the signal must be passed through analog-to-digital converter(ADC). Photons of light hit the photosites, thus accumulating electrical charges. Then the ADC measures the amt which is considered analog info. It then converts to the binary info.

Photosites and Pixels
"A camera claims to be a 2.1-megapixel camera and it is capable of producing images with a resolution of 1600x1200. Let's do the math: a 1600x1200 image contains 1,920,000 pixels."
Well, this is the camera indeed has 2.1 million photosites on the CCD, just that some of the photosites aren't used for imaging. Since CCD is an analog device, some sort of circuitry(dyed black so doesn't absorb light) is needed to connect to the ADC so that it can measure the amt of charges.

These are egs of storage systems used in digital cameras:

• Built-in memory- built-in flash memory
• SmartMedia card
• CompactFlash
• Memory Stick
• Floppy disk
• Hard disk
• Writeable CD and DVD

The two main file formats used by digital cameras are TIFF and JPEG. TIFF is an uncompressed format and JPEG is a compressed format. Most cameras use the JPEG file format for storing pictures, and they sometimes offer quality settings (such as medium or high).

Compression

Some of the patterns repeat over again in a picture, like the blue sky... thus digicam makes use of repeated pattern to create exactly the same effect and this is known as repetition.

Some compression throw away certain meaningless data. Thus lower the resolution, more data is thrown out. This is known as irrelevancy.

Controlling Light

The word camera comes from the term camera obscura. Camera meaning room or chamber and obscura meaning dark. Thus camera means dark room. It is crucial to control the amt of light entering because if too much light enters, some info would be lostbecasue the sensor cannot hold any more of the light.

Aperture is the small opening found in the camera and is located at the back of the lens. On a very bright day, the light reflected off your image may be very intense, thus a small aperture is needed. Likewise, if it is a cloudy day, aperture should be enlarged to produce a brighter image. Interestingly, this works out to be the same as the pupil of our eye. Our pupil tends to dilate when we are in a dark room and shrink when we are under the sun.

Shutter speed

Basically, it means the amt of time light is allowed to enter the aperture. Film-based camera has mechanical shutter. So if u expose ur film, it can't be wiped clean again. However, the sensor in a digital camera can be easily resetted every time and it is called digital shutter.